Engineers gets excited by the details of a solution and try to sell on those. But end users typically want the problem to be solved with minimal fuss and effort. Details are off putting because they require effort to understand! Focus on how you will make things simpler.
Am an expert, and I think this speaks to the crux of how bad software sells: you can hide the shortcomings by leaving out details, and a lot of customers are fine (and sometimes happy!) with that. On the other hand, a truly excellent product lets you keep the marketing simple too; so simple in fact, I would argue that the most popular software products out there don't require much marketing at all since they're fully word of mouth now, or even de facto mandated like git and various shells.
Engineers gets excited by the details of a solution and try to sell on those. But end users typically want the problem to be solved with minimal fuss and effort. Details are off putting because they require effort to understand! Focus on how you will make things simpler.